Observational Derivation of Einstein's``Law of the Constancy of the Velocity of Light in Vacuo"

On the basis of Galilean invariance and the Doppler formula, combined with an observational condition, it is shown that the constancy of the velocity of light {\it in vacuo} can be derived, together with time-dilatation and Lorentz contraction. It is not necessary to take the constancy as a postulate.Comment: 5 pages AIP-tex. Conference "Quantum Theory: Reconsideration of Foundations 3", Vaxjo Sweden, June 2005. To appear in AIP conference serie

Bath generated work extraction in two-level systems

The spin-boson model, often used in NMR and ESR physics, quantum optics and spintronics, is considered in a solvable limit to model a spin one-half particle interacting with a bosonic thermal bath. By applying external pulses to a non-equilibrium initial state of the spin, work can be extracted from the thermalized bath. It occurs on the timescale T_2 inherent to transversal (`quantum') fluctuations. The work (partly) arises from heat given off by the surrounding bath, while the spin entropy remains constant during a pulse. This presents a violation of the Clausius inequality and the Thomson formulation of the second law (cycles cost work) for the two-level system.Comment: 5 pages Latex, uses aip-proceedings style files. Proceedings `Quantum Limits to the Second Law', San Diego, July 200

Association of Factor V Secretion with Protein Kinase B Signaling in Platelets from Horses with Atypical Equine Thrombasthenia.

BackgroundTwo congenital bleeding diatheses have been identified in Thoroughbred horses: Glanzmann thrombasthenia (GT) and a second, novel diathesis associated with abnormal platelet function in response to collagen and thrombin stimulation.Hypothesis/objectivesPlatelet dysfunction in horses with this second thrombasthenia results from a secretory defect.AnimalsTwo affected and 6 clinically normal horses.MethodsEx vivo study. Washed platelets were examined for (1) expression of the αIIb-β3 integrin; (2) fibrinogen binding capacity in response to ADP and thrombin; (3) secretion of dense and α-granules; (4) activation of the mammalian target of rapamycin (mTOR)-protein kinase B (AKT) signaling pathway; and (5) cellular distribution of phosphatidylinositol-4-phosphate-3-kinase, class 2B (PIK3C2B) and SH2 containing inositol-5'-phosphatase 1 (SHIP1).ResultsPlatelets from affected horses expressed normal amounts of αIIb-β3 integrin and bound fibrinogen normally in response to ADP, but bound 80% less fibrinogen in response to thrombin. α-granules only released 50% as much Factor V as control platelets, but dense granules released their contents normally. Protein kinase B (AKT) phosphorylation was reduced after thrombin activation, but mTOR Complex 2 (mTORC2) and phosphoinositide-dependent kinase 1 (PDK1) signaling were normal. SH2-containing inositol-5'-phosphatase 1 (SHIP1) did not localize to the cytoskeleton of affected platelets and was decreased overall consistent with reduced AKT phosphorylation.Conclusions and clinical significanceDefects in fibrinogen binding, granule secretion, and signal transduction are unique to this thrombasthenia, which we designate as atypical equine thrombasthenia

The HPST Framework: A Case Study on an Organizational Tool Used to Understand Historical Narrative in a Social Studies Classroom

This dissertation chronicled a multifaceted study utilizing the Historical, Philosophical, Societal and a Takeaway (HPST) Framework; an organizational tool used for document analysis. Utilizing a case study format, this research unpacked how a charter school teacher used HPST within her own ninth grade Advanced Placement World History class. As a starting point, I offered an account of my own autobiographical narrative, chronicling through my attempt at ethnographic writing and infused with scholarly literature as needed. Consequently, this personal narrative was coupled with my professional experiences within the Social Studies field. Upon this foundation, this study explored the use of the HPST Framework for analyzing narratives and its complexities beyond the textbook. The intent of HPST was to help students analyze the interaction of the author, the text, and the reader. The research was geared to see to what degree students might draw out historical, philosophic, and socio-cultural frames reflected as complicated conversations. In particular, I was interested in examining U.S. students’ portrayals of marginalized groups within a context of world history and how these roles changed after students used the HPST Framework to analyze narrative passages. The study uncovered that HPST could add to literature by prioritizing historical narratives to convey information through stories which humanize the people involved in significant world events. For this teacher, HPST served as a platform for student discussion because it took the existing classroom discourse about philosophy, politics, society, or power and cognitively arranged it in two levels for students to engage with the text and the author. This was followed by an analytical layer to enhance comprehension and critical thinking. With that said, students could easily identify the H and S; however, challenges were found in their understanding of the P. Moreover, HPST allowed students to engage in discovery learning instead of prescribed analysis by the teacher. Additionally, discussions were offered as to how this teacher with limited time or a restricted curriculum could modify HPST and still use it. Lastly, discourses were given as to how this educator used narratives in the past and how her teaching changed because of the HPST

Teachers’ experiences and perceptions regarding mobile augmented reality games: a case study of a teacher training

The literature has been recognizing the potential of mobile technologies, augmented reality (AR) and game-based approaches in Education and recommends its adoption. Considering the scarcity of this type of educational resources in the Portuguese context, it is relevant to create opportunities for teachers and researchers to collaborate in the development of high-quality open resources to be integrated into games available for all. To this end, a 50-hour continuous training course for teachers was conducted to promote collaborative development of mobile AR game-based resources for Science, Technology, Engineering and Mathematics learning. In this contribution, data from a questionnaire applied at the beginning of the training is analysed to support assessment of teachers’ previous experiences and initial perceptions regarding mobile learning, AR use in Education and game-based learning. The questionnaire was anonymous and 14 out of 16 teachers gave informed consent to participate in this study. This data was triangulated with information collected through participant observation from two researchers who were also the trainers and the authors of this paper. Results reveal that teachers with different profiles attained this training. Nevertheless, most teachers revealed naïve perspectives on mobile and game-based learning and were unaware of AR technologies and their potential use in education. Teacher profiles varied from those who acknowledge not knowing and not using either of the three approaches in their teaching practices, nor in their personal learning experiences, to those who seem to have somewhat accurate ideas. This work is relevant as this case study is an empirical account of teachers practices and perspectives on mobile AR games.publishe

HeteroGenius: A Framework for Hybrid Analysis of Heterogeneous Software Specifications

Nowadays, software artifacts are ubiquitous in our lives being an essential part of home appliances, cars, cell phones, and even in more critical activities like aeronautics and health sciences. In this context software failures may produce enormous losses, either economical or, in the worst case, in human lives. Software analysis is an area in software engineering concerned with the application of diverse techniques in order to prove the absence of errors in software pieces. In many cases different analysis techniques are applied by following specific methodological combinations that ensure better results. These interactions between tools are usually carried out at the user level and it is not supported by the tools. In this work we present HeteroGenius, a framework conceived to develop tools that allow users to perform hybrid analysis of heterogeneous software specifications. HeteroGenius was designed prioritising the possibility of adding new specification languages and analysis tools and enabling a synergic relation of the techniques under a graphical interface satisfying several well-known usability enhancement criteria. As a case-study we implemented the functionality of Dynamite on top of HeteroGenius.Comment: In Proceedings LAFM 2013, arXiv:1401.056